EVERYTHING: Beware of Spoilers, I've read all 40, including the Last Hope (the book that ends the series)
Rusty comes to the clan. He befriends Ravenpaw and Graypaw. Soon after he gets his apprentice name - Firepaw - Ravenpaw comes back from a battle for Sunning Rocks (a border between Riverclan and Thunderclan, that the cats are constantly fighting over) saying that the Deputy - Redtail - had been killed in battle. Secretly, Ravenpaw knows what really happened. Tigerclaw had told everyone that Oakheart - Deputy of Riverclan - killed Redtail, and Tigerclaw killed Oakheart. But Ravenpaw saw what really happened: After Tigerclaw killed Oakheart, he saw the perfect chance to kill Redtail and become Deputy himself... After that his ambition overtook him and he kept doing evil things, ect. Tigerclaw realizes that Ravenpaw saw and starts plotting to kill him, but Firepaw and Graypaw help him escape to alive in a barn for the rest of his life. Later on Graypaw becomes Graystripe and Firepaw becomes Fireheart. If I remember right, Windclan was chased out by Shadowclan and Graystripe and Fireheart brought them back. Then Bluestar realizes how evil Tigerclaw is (After he tries to kill her. Oh ya, and Fireheart got an apprentice, Cinderpaw, that was crippled and became Cinderpelt - Medicine cat after Yellowfang died) evil and banishes him. yada yada... He takes over Shadowclan, tries to take over all clans, brings Bloodclan into the forest. Gets killed by Bloodclan's leader Scourge. Oh, and he also unleashes giant dogs that kill Swiftpaw, ruin Brightpaw's face, and kill bluestar. Firestar becomes FireSTAR. Then Twolegs destroy the forest, so the cats move to the lake territory. Uh... In the end Firestar catches on fire and dies (pathetic death, amirite?) idk, there's WAY too much to tell (there are even three cats with super powers O.o) so it'd be easier if you just asked ME question (how does ___ die, what is ___'s future like, Who's ___'s mate and kits, ect.)